Improvement in hydraulic elevators



O. R. OTIS. Hydraulic-Elevator.

No. 205,895. Patented July 9, 1878.

fQZk I/ Even/101'- N.PE|'ERS, PHOTO-LITHOGRAPHER, WASH ON. D C- UNITEDSTATES PATENT OEEIcE.

CHARLES R. OTIS, OF YONKERS, YE YORK.

IMPROVEMENT IN HYDRAULIC ELEVATORS.

Specification forming part of Letters Patent No. 205,895, dated July 9,H 7 application filed January 12, 1878.

To all whom it may concern:

Be it known that I, OHARLEs R. OTIS, of Yonkers, in the county ofVVestchester and State of New York, have invented certain new and usefulImprovements in Hydraulic Elevators, of which the following is adescription, reference being had to the accompanying drawing, formingpart of this specification.

This invention more particularly relates to hydraulic elevators in whichsupply-tanks, arranged at different altitudes, are used; and theinvention generally consists in certain novel combinations of devices,whereby, while an intermediate or lower head or pressure may be employedfor lighter loads or the ordinary work of the elevator, a temporaryincreased pressure is obtained in starting the load, and the pressuremay be increased at pleasure for lifting heavier loads by drawing waterfrom an upper tank without its passage through the under tank,substantially as hereinafter described.

Figure 1 represents a side elevation of a hydraulic elevator constructedin accordance with my invention. Fig. 2 is a horizontal sec tion of thesame on the irregular line as w,- and Fig. 3 is a sectional elevationthereof, in part, mainly on the irregular line y y.

A is an upper tank, which may be placed at the top of the buildingcontaining the elevator or hoisting apparatus, and which may be leftopen at its top. B is an additional tank, arranged to occupy anintermediate po sition or altitude, which may be midway be tween theupper tank A and the motor 0, which actuates the ear D by means of arope or chain, b, and pulleys c c d. This intermediate tank B is closedat its top and made capable of sustaining a superincumbent pressure, dueto a column of water in a pipe, 6, connecting the tank A with theintermediate tank B.

ferred to, said water in its descent to the motor does not pass throughthe intermediate tank B, but is conveyed by a separate supplypipe, f,directly from the bottom of the tank A to the motor.

Another pipe, connects the bottom of the intermediate tank B with themotor supplypipe f at a point in the latter which is at or below thelevel of the bottom of said tank. This pipe or connection 9 is fittedwith a check-valve, h, which prevents water from the upper tank passingto the intermediate tank.

The supply-pipe f is provided above the pipe or connection 9 with astop-cock or valve, i, which is preferably self-closing, and which isconnected, by means of a rod, rope, or chain, k, and pulleys l, or othersuitable contrivances, with a treadle or hand mechanism, m, within reachof the operator in the car, so that said valve t may be opened by theoperator whenever it is required to bring into use the superior pressureof the water as derived from the upper tank A, as, for instance, inlifting a heavy load. At all other times, however, this valve '5 in thepipe f leading to the upper tank A will remain closed, thus leaving thewater in the intermediate tank B to act as the main source of supply inworking the elevator or its car for ordinary or light loads.

G is the usual main hand-rope, by which the action of the motor tocontrol the motion of the car is controlled, said rope passing over oraround pulleys n n 0, and serving, by suitable mechanical devices, tocontrol a valve, H, in the supply-pipe f, which valve is arranged belowthe intermediate tank B. So long as the operator makes use of this mainhand-rope G the water to operate the motor will be drawn exclusivelyfrom the intermediate tank B, subject only, when the pump E is inoperation and water is passing to the upper tank, to the additionalpressure of the column of water in the pipe 0; but the quantity of waterin this pipe will soon be exhausted, and only exerts an additional forcein starting the ear to overcome the inertia of the apparatus, the pipe0, by its delivery end, terminating in the upper portion of the tank A,not drawing water from said tank A. This connecting pressure or supplypipe e between the two tanks A and B is consequently a valuable adjunctto the apparatus when starting the car; but after the latter has beenfairly started, the draft to supply the motor is taken from the lowertank I \Yhen it is required to lift a heavier load than the water in thetank ll by its restricted altitude is capable of accomplishing,then theoperator, by means of the rod, rope. or chain 1., opens the valve 1',and thereby causes the draft of water to supply the motor to he takenfrom the upper tank A.

The economy of thus working the elevator will be obvious from the factthat the cost of pumping water depemls upon the height to which it israised. For all ordinary loads the supply will be drawn from theintermediate tank 1:, which. it placed midway between the pump and theupper tank, is supplied or kept tilled with water at one-halt'the costof supplying the upper tank, while for starting the elevator. when morepower is required than to keep it in motion after having been started,atemporary higher head of water, due to the column in the pipe 1'connecting the intermel diate tank with the top of the upper tank, is Iobtained.

This invent ion accordinglydifilrs from other hydraulic elevators inwhich tanks placed at different altitudes have been used, and whenrequiring to use a much heavier continuous pressure than is derivablefrom the intermediate tank. the water, in being drawn from the uppertank by opening the valve 4'. does not pass through the intermediatetank to the motor, but directly to the latter, so that the intermediatetank may be kept charged with water for subsequently lifting a lighterload, or for the ordinary work 01' the elevator.

l is a waste-water vessel or chamber for receiving the spent water fromthe motor, aml serving also as a reservoir for resupplying the tanks Aaml ll, thus using the same water over and over again. lioth of thesetanks A and 13 should or may be provided with floats r .s' inindependent connection with a rope, u, for automatically controlling theinlet-valve uof the steam-pump li to keep said tanks tilled with water,and for stopping the pump when both tanks are fully charged. Theselastnamed devices, however, t'orm no part of this invention.

Instead of running the supply-pipe 0 to the top ot'the uppertank A, itmay be connected to the bottom of said tank without changing the generaloperation hereinbefore described by simply placing a check-valve in saidpipe where it connects to the tank, to prevent the water, by the closingof said valve, from passing to the lower tank from the upper one, anairvalve opening inward also being attached to the pipe 0, immediatelybelow the upper tank, to prevent the formation of a vacuum in said pipewhen drawing out water through the lower tank. Such modification,however, which involves the use of special valves, is less simple thanthe one hereinbefore described, and reduces the height of the column inthe pipe 0, available as an auxiliary starting force, to a degree orextent which is equal to the depth or height of the upper tank A.

l urthermore, in the invention which I have here described a leadingcharacteristic is the combination of the closed tank I the open tank A,and the motor U; aml another prominent feature of the invention is thecombination of the closed tank B and the motor (7 with the pipe 0,operating to give a temporary increased pressure when starting theelevator.

1 claim-- 1. The combination of the closed tank It and the open tank Awith the motor substantially as specified.

2. The combination of the closed tank B aml the motor (J with thewater-pipe 0, whereby a temporary increased pressure is obtained whenstarting the elevator, essentially as described.

3. In a hydraulic elevator having supplytanks arranged at differentaltitudes, the combination, with the supply pipe or pipes to the motorfrom said tanks, of an independent conneeting pressure or supply pipe,0, between the upper portion of the upper tank and the intermediate orlower tank, substantially as and for the purpose or purposes herein setforth.

4. The combination, with the upper tank A and lower or intermediate tankB, of the suppl y-pipe f, connecting the motor of the elevator with theupper tank A, the pipe g, connecting the intermediate tank with the pipef, a checkvalve, 1:, applied to said pipe g, and a valve, i, arranged tointercept the water in the pipe f above the pipe g, and made capable ofcontrol by the operator, essentially as described.

5. The combination of the independent connecting pressure and supplypipe c with the upper and lower tanks A 13, the supply-pipe f to themotor from the upper tank, the valve 11 in said pipe f, subject tocontrolby the operator, and the pipe 9, provided with a check-valve, h,and connecting the pipe f below the valve 1' with the lower tank 13,substantially as specified.

tllAs. P. OTIS.

Witnesses:

Finn). I IAYNns, \nmvon II. IIAnnIs.

